A centrifugal pelleting operation is a common procedure used to separate solid particles (such as cells or portions of cells, particulates, aggregates, compounds and the like) suspended in a liquid. In a pelleting operation, a container, typically a test tube or a flexible bag, holding a liquid suspension is placed in a bucket of a centrifuge rotor and subjected to a centrifugal force field. Centrifugal force causes the solid material to separate from the liquid supernatant and to deposit in a clump, called a pellet, on the wall of the container perpendicular to the axis of rotation, typically at the base of the container. When the liquid is withdrawn from the container, the pellet may be removed or may be resuspended for further processing.
Such centrifuges are used in biological research and medicine. Often, the pelleted particles are of small quantity or are valuable. Very careful and delicate technique is required by the technician handling the pellets in order to prevent loss of particles or of a patient's cells from the pellet during further manipulations. This adds additional time to the process and requires skilled, highly trained handlers. Neither of these is always available and when available, add to the costs of the procedure.
In view of the foregoing, it is believed advantageous to provide an apparatus that facilitates the simple removal of supernatant from the container after centrifugation and also facilitates further manipulations of the pelleted particles without loss of partides. An apparatus that also would lend itself to incorporation into a closed system that limits direct handling of patent samples and facilitates the use of flexible cell bags for processing patient cells would be additionally beneficial.